A=[1 0; 0 -1];
D=[4  2  5 4; 0  2  3 0];
Dp=A*D

plot(D(1,:),D(2,:),'b',Dp(1,:),Dp(2,:),'r')
axis square
axis([-6 6 -6 6])
xlabel('x')
ylabel('y')
grid on
text(3.5,1,'D')
text(3.5,-1,'D''')

